Optical imaging lens including eight senses of +−+−+−+−, +−−−+−+−or +−+−−−+−refractive powers

ABSTRACT

The present invention provides an optical imaging lens. The optical imaging lens comprises eight lens elements positioned in an order from an object side to an image side. Through controlling the convex or concave shape of the surfaces of the lens elements, the optical imaging lens may enlarge aperture stop and image height and increase resolution.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to P.R.C. Patent Application No. 202010824313.4 titled “Optical Imaging Lens,” filed Aug. 17, 2020, with the State Intellectual Property Office of the People's Republic of China (SIPO).

TECHNICAL FIELD

The present disclosure relates to optical imaging lenses, and particularly, optical imaging lenses of mobile electronic devices.

BACKGROUND

As the specifications of mobile electronical devices, such as cell phones, digital cameras, tablet computers, personal digital assistants (PDA), etc. rapidly evolve, various types of key components, such as optical imaging lenses, are developed. Desirable objectives for designing an optical imaging lens may not be limited to large aperture and short system length, but may also include great pixels and better resolution. Great pixels implies great image height which may be carried out with a great image sensor receiving imaging light. Large aperture may allow optical imaging lenses receiving more imaging rays; however, to design such optical imaging lenses is more difficult. When considering both large aperture and great pixels, it is even more difficult to design optical imaging lenses. Accordingly, designing an optical imaging lens with multiple lens elements within a limited system length presenting great resolution and enlarged aperture and image height may be goals of research and design in the industry.

SUMMARY

The present disclosure provides for optical imaging lenses enlarging aperture stop and image height and increasing resolution in view of achieving good imaging quality.

In an example embodiment, an optical imaging lens may comprise eight lens elements, hereinafter referred to as first, second, third, fourth, fifth, sixth, seventh and eighth lens element and positioned sequentially from an object side to an image side along an optical axis. Each of the first, second, third, fourth, fifth, sixth, seventh and eighth lens element may also have an object-side surface facing toward the object side and allowing imaging rays to pass through and an image-side surface facing toward the image side and allowing the imaging rays to pass through.

In the specification, parameters used here are defined as follows: a thickness of the first lens element along the optical axis is represented by T1, a distance from the image-side surface of the first lens element to the object-side surface of the second lens element along the optical axis, i.e. an air gap between the first and second lens elements along the optical axis, is represented by G12, a thickness of the second lens element along the optical axis is represented by T2, a distance from the image-side surface of the second lens element to the object-side surface of the third lens element along the optical axis, i.e. an air gap between the second and third lens elements along the optical axis, is represented by G23, a thickness of the third lens element along the optical axis is represented by T3, a distance from the image-side surface of the third lens element to the object-side surface of the fourth lens element along the optical axis, i.e. an air gap between the third and fourth lens elements along the optical axis, is represented by G34, a thickness of the fourth lens element along the optical axis is represented by T4, a distance from the image-side surface of the fourth lens element to the object-side surface of the fifth lens element along the optical axis, i.e. an air gap between the fourth and fifth lens elements along the optical axis, is represented by G45, a thickness of the fifth lens element along the optical axis is represented by T5, a distance from the image-side surface of the fifth lens element to the object-side surface of the sixth lens element along the optical axis, i.e. an air gap between the fifth and sixth lens elements along the optical axis, is represented by G56, a thickness of the sixth lens element along the optical axis is represented by T6, a distance from the image-side surface of the sixth lens element to the object-side surface of the seventh lens element along the optical axis, i.e. an air gap between the sixth and seventh lens elements along the optical axis, is represented by G67, a thickness of the seventh lens element along the optical axis is represented by T7, an air gap between the seventh and eighth lens elements along the optical axis, is represented by G78, a thickness of the eighth lens element along the optical axis is represented by T8, a distance from the image-side surface of the eighth lens element to the object-side surface of the filtering unit along the optical axis is represented by G8F, a thickness of the filtering unit along the optical axis is represented by TTF, a distance from the image-side surface of the filtering unit to the image plane along the optical axis is represented by GFP, a focal length of the first lens element is represented by f1, a focal length of the second lens element is represented by f2, a focal length of the third lens element is represented by f3, a focal length of the fourth lens element is represented by f4, a focal length of the fifth lens element is represented by f5, a focal length of the sixth lens element is represented by f6, a focal length of the seventh lens element is represented by f7, a focal length of the eighth lens element is represented by f8, a refractive index of the first lens element is represented by n1, a refractive index of the second lens element is represented by n2, a refractive index of the third lens element is represented by n3, a refractive index of the fourth lens element is represented by n4, a refractive index of the fifth lens element is represented by n5, a refractive index of the sixth lens element is represented by n6, a refractive index of the seventh lens element is represented by n7, a refractive index of the eighth lens element is represented by n8, an abbe number of the first lens element is represented by V1, an abbe number of the second lens element is represented by V2, an abbe number of the third lens element is represented by V3, an abbe number of the fourth lens element is represented by V4, an abbe number of the fifth lens element is represented by V5, an abbe number of the sixth lens element is represented by V6, an abbe number of the seventh lens element is represented by V7, an abbe number of the eighth lens element is represented by V8, an effective focal length of the optical imaging lens is represented by EFL, a distance from the object-side surface of the first lens element to the image-side surface of the eighth lens element along the optical axis is represented by TL, a distance from the object-side surface of the first lens element to the image plane along the optical axis, i.e. a system length, is represented by TTL, a distance from the object-side surface of the first lens element to the object-side surface of the fifth lens element along the optical axis is represented by D11t51, a distance from the image-side surface of the first lens element to the object-side surface of the fifth lens element along the optical axis is represented by D12t51, a sum of the thicknesses of all eight lens elements from the first lens element to the eighth lens element along the optical axis is represented by ALT, a sum of seven air gaps from the first lens element to the eighth lens element along the optical axis, i.e. a sum of G12, G23, G34, G45, G56, G67 and G78, is represented by AAG, a distance from the image-side surface of the eighth lens element to the image plane along the optical axis is represented by BFL, a half field of view of the optical imaging lens is represented by HFOV, an image height of the optical imaging lens is represented by ImgH, and a f-number of the optical imaging lens is represented by Fno.

In an aspect of the present disclosure, in the optical imaging lens, the fourth lens element has negative refracting power, an optical axis region of the object-side surface of the fifth lens element is concave, the sixth lens element has negative refracting power and a periphery region of the image-side surface of the sixth lens element is convex, and an optical axis region of the image-side surface of the eighth lens element is concave. Lens elements included by the optical imaging lens are only the eight lens elements described above, and the optical imaging lens satisfies the inequality: V1+V2+V3≤115.000  Inequality (1).

In another aspect of the present disclosure, in the optical imaging lens, the second lens element has negative refracting power, the fourth lens element has negative refracting power, an optical axis region of the object-side surface of the fifth lens element is concave, the sixth lens element has negative refracting power, and an optical axis region of the image-side surface of the eighth lens element is concave. Lens elements included by the optical imaging lens are only the eight lens elements described above, and the optical imaging lens satisfies the inequality: V1+V3≤100.000  Inequality (2).

In another aspect of the present disclosure, in the optical imaging lens, the second lens element has negative refracting power, the fourth lens element has negative refracting power, an optical axis region of the object-side surface of the fifth lens element is concave, the sixth lens element has negative refracting power, the seventh lens element has positive refracting power, and an optical axis region of the image-side surface of the eighth lens element is concave. Lens elements included by the optical imaging lens are only the eight lens elements described above, and the optical imaging lens satisfies the inequality: V3+V7≤100.000  Inequality (3).

In another example embodiment, other inequality(s), such as those relating to the ratio among parameters could be taken into consideration. For example: V3+V4+V5+V6+V7+V8≤235.000  Inequality (4); 3.300≤(EFL/Fno+ImgH)/D11t51  Inequality (5); D11t51/(T5+G56)≤3.600  Inequality (6); D12t51/(T6+G56)≤1.800  Inequality (7); D12t51/T8≤3.600  Inequality (8); AAG/(T8+G78)≤2.000  Inequality (9); V3+V8≤95.000  Inequality (10); 8.750≤(EFL/Fno+ImgH)/BFL  Inequality (11); (T6+G67+T7)/T1≤1.800  Inequality (12); ALT/AAG≤2.200  Inequality (13); (T2+G34+T6+G67+T7)/(T5+G56)≤2.600  Inequality (14); (T2+G12+T6+G67+T7)/(T4+T5)≤2.000  Inequality (15); V3+V5≤100.000  Inequality (16); (T1+T3+T6+T7)/(G12+G78)≤9.000  Inequality (17); (T3+T4+T6+T7)/(G45+G56)≤4.400  Inequality (18); (G23+T3+G34+T7)/G78≤8.000  Inequality (19); and/or TTL/(G56+G78)≤10.000  Inequality (20).

In some example embodiments, more details about the convex or concave surface structure, refracting power or chosen material etc. could be incorporated for one specific lens element or broadly for a plurality of lens elements to improve the control for the system performance and/or resolution. It is noted that the details listed herein could be incorporated in example embodiments if no inconsistency occurs.

The optical imaging lens in example embodiments may enlarge aperture stop and image height and increase resolution in view of achieving good imaging quality.

BRIEF DESCRIPTION OF THE DRAWINGS

Example embodiments will be more readily understood from the following detailed description when read in conjunction with the appended drawing, in which:

FIG. 1 depicts a cross-sectional view of one single lens element according to the present disclosure;

FIG. 2 depicts a cross-sectional view showing the relation between the shape of a portion and the position where a collimated ray meets the optical axis;

FIG. 3 depicts a cross-sectional view showing a first example of determining the shape of lens element regions and the boundaries of regions;

FIG. 4 depicts a cross-sectional view showing a second example of determining the shape of lens element regions and the boundaries of regions;

FIG. 5 depicts a cross-sectional view showing a third example of determining the shape of lens element regions and the boundaries of regions;

FIG. 6 depicts a cross-sectional view of a first embodiment of an optical imaging lens having eight lens elements according to the present disclosure;

FIG. 7 depicts a chart of a longitudinal spherical aberration and other kinds of optical aberrations of a first embodiment of the optical imaging lens according to the present disclosure;

FIG. 8 depicts a table of optical data for each lens element of a first embodiment of an optical imaging lens according to the present disclosure;

FIG. 9 depicts a table of aspherical data of a first embodiment of the optical imaging lens according to the present disclosure;

FIG. 10 depicts a cross-sectional view of a second embodiment of an optical imaging lens having eight lens elements according to the present disclosure;

FIG. 11 depicts a chart of a longitudinal spherical aberration and other kinds of optical aberrations of a second embodiment of the optical imaging lens according to the present disclosure;

FIG. 12 depicts a table of optical data for each lens element of the optical imaging lens of a second embodiment of the present disclosure;

FIG. 13 depicts a table of aspherical data of a second embodiment of the optical imaging lens according to the present disclosure;

FIG. 14 depicts a cross-sectional view of a third embodiment of an optical imaging lens having eight lens elements according to the present disclosure;

FIG. 15 depicts a chart of a longitudinal spherical aberration and other kinds of optical aberrations of a third embodiment of the optical imaging lens according to the present disclosure;

FIG. 16 depicts a table of optical data for each lens element of the optical imaging lens of a third embodiment of the present disclosure;

FIG. 17 depicts a table of aspherical data of a third embodiment of the optical imaging lens according to the present disclosure;

FIG. 18 depicts a cross-sectional view of a fourth embodiment of an optical imaging lens having eight lens elements according to the present disclosure;

FIG. 19 depicts a chart of a longitudinal spherical aberration and other kinds of optical aberrations of a fourth embodiment of the optical imaging lens according to the present disclosure;

FIG. 20 depicts a table of optical data for each lens element of the optical imaging lens of a fourth embodiment of the present disclosure;

FIG. 21 depicts a table of aspherical data of a fourth embodiment of the optical imaging lens according to the present disclosure;

FIG. 22 depicts a cross-sectional view of a fifth embodiment of an optical imaging lens having eight lens elements according to the present disclosure;

FIG. 23 depicts a chart of a longitudinal spherical aberration and other kinds of optical aberrations of a fifth embodiment of the optical imaging lens according to the present disclosure;

FIG. 24 depicts a table of optical data for each lens element of the optical imaging lens of a fifth embodiment of the present disclosure;

FIG. 25 depicts a table of aspherical data of a fifth embodiment of the optical imaging lens according to the present disclosure;

FIG. 26 depicts a cross-sectional view of a sixth embodiment of an optical imaging lens having eight lens elements according to the present disclosure;

FIG. 27 depicts a chart of a longitudinal spherical aberration and other kinds of optical aberrations of a sixth embodiment of the optical imaging lens according the present disclosure;

FIG. 28 depicts a table of optical data for each lens element of the optical imaging lens of a sixth embodiment of the present disclosure;

FIG. 29 depicts a table of aspherical data of a sixth embodiment of the optical imaging lens according to the present disclosure;

FIG. 30 depicts a cross-sectional view of a seventh embodiment of an optical imaging lens having eight lens elements according to the present disclosure;

FIG. 31 depicts a chart of a longitudinal spherical aberration and other kinds of optical aberrations of a seventh embodiment of the optical imaging lens according to the present disclosure;

FIG. 32 depicts a table of optical data for each lens element of a seventh embodiment of an optical imaging lens according to the present disclosure;

FIG. 33 depicts a table of aspherical data of a seventh embodiment of the optical imaging lens according to the present disclosure;

FIG. 34 depicts a cross-sectional view of an eighth embodiment of an optical imaging lens having eight lens elements according to the present disclosure;

FIG. 35 depicts a chart of a longitudinal spherical aberration and other kinds of optical aberrations of an eighth embodiment of the optical imaging lens according to the present disclosure;

FIG. 36 depicts a table of optical data for each lens element of an eighth embodiment of an optical imaging lens according to the present disclosure;

FIG. 37 depicts a table of aspherical data of an eighth embodiment of the optical imaging lens according to the present disclosure;

FIG. 38 depicts a table for the values of V1+V2+V3, V1+V3, V3+V7, V3+V4+V5+V6+V7+V8, (EFL/Fno+ImgH)/D11t51, D11t51/(T5+G56), D12t51/(T6+G56), D12t51/T8, AAG/(T8+G78), V3+V8, (EFL/Fno+ImgH)/BFL, (T6+G67+T7)/T1, ALT/AAG, (T2+G34+T6+G67+T7)/(T5+G56), (T2+G12+T6+G67+T7)/(T4+T5), V3+V5, (T1+T3+T6+T7)/(G12+G78), (T3+T4+T6+T7)/(G45+G56), (G23+T3+G34+T7)/G78 and TTL/(G56+G78) of all eight example embodiments.

DETAILED DESCRIPTION

For a more complete understanding of the present disclosure and its advantages, reference is now made to the following description taken in conjunction with the accompanying drawings, in which like reference numbers indicate like features. Persons of ordinary skill in the art having the benefit of the present disclosure will understand other variations for implementing embodiments within the scope of the present disclosure, including those specific examples described herein. The drawings are not limited to specific scale and similar reference numbers are used for representing similar elements. As used in the disclosures and the appended claims, the terms “example embodiment,” “exemplary embodiment,” and “present embodiment” do not necessarily refer to a single embodiment, although it may, and various example embodiments may be readily combined and interchanged, without departing from the scope or spirit of the present disclosure. Furthermore, the terminology as used herein is for the purpose of describing example embodiments only and is not intended to be a limitation of the disclosure. In this respect, as used herein, the term “in” may include “in” and “on”, and the terms “a”, “an” and “the” may include singular and plural references. Furthermore, as used herein, the term “by” may also mean “from”, depending on the context. Furthermore, as used herein, the term “if” may also mean “when” or “upon”, depending on the context. Furthermore, as used herein, the words “and/or” may refer to and encompass any and all possible combinations of one or more of the associated listed items.

The terms “optical axis region”, “periphery region”, “concave”, and “convex” used in this specification and claims should be interpreted based on the definition listed in the specification by the principle of lexicographer.

In the present disclosure, the optical system may comprise at least one lens element to receive imaging rays that are incident on the optical system over a set of angles ranging from parallel to an optical axis to a half field of view (HFOV) angle with respect to the optical axis. The imaging rays pass through the optical system to produce an image on an image plane. The term “a lens element having positive refracting power (or negative refracting power)” means that the paraxial refracting power of the lens element in Gaussian optics is positive (or negative). The term “an object-side (or image-side) surface of a lens element” refers to a specific region of that surface of the lens element at which imaging rays can pass through that specific region. Imaging rays include at least two types of rays: a chief ray Lc and a marginal ray Lm (as shown in FIG. 1 ). An object-side (or image-side) surface of a lens element can be characterized as having several regions, including an optical axis region, a periphery region, and, in some cases, one or more intermediate regions, as discussed more fully below.

FIG. 1 is a radial cross-sectional view of a lens element 100. Two referential points for the surfaces of the lens element 100 can be defined: a central point, and a transition point. The central point of a surface of a lens element is a point of intersection of that surface and the optical axis I. As illustrated in FIG. 1 , a first central point CP1 may be present on the object-side surface 110 of lens element 100 and a second central point CP2 may be present on the image-side surface 120 of the lens element 100. The transition point is a point on a surface of a lens element, at which the line tangent to that point is perpendicular to the optical axis I. The optical boundary OB of a surface of the lens element is defined as a point at which the radially outermost marginal ray Lm passing through the surface of the lens element intersects the surface of the lens element. All transition points lie between the optical axis I and the optical boundary OB of the surface of the lens element. If multiple transition points are present on a single surface, then these transition points are sequentially named along the radial direction of the surface with reference numerals starting from the first transition point. For example, the first transition point, e.g., TP1, (closest to the optical axis I), the second transition point, e.g., TP2, (as shown in FIG. 4 ), and the Nth transition point (farthest from the optical axis I).

The region of a surface of the lens element from the central point to the first transition point TP1 is defined as the optical axis region, which includes the central point. The region located radially outside of the farthest Nth transition point from the optical axis I to the optical boundary OB of the surface of the lens element is defined as the periphery region. In some embodiments, there may be intermediate regions present between the optical axis region and the periphery region, with the number of intermediate regions depending on the number of the transition points.

The shape of a region is convex if a collimated ray being parallel to the optical axis I and passing through the region is bent toward the optical axis I such that the ray intersects the optical axis I on the image side A2 of the lens element. The shape of a region is concave if the extension line of a collimated ray being parallel to the optical axis I and passing through the region intersects the optical axis I on the object side A1 of the lens element.

Additionally, referring to FIG. 1 , the lens element 100 may also have a mounting portion 130 extending radially outward from the optical boundary OB. The mounting portion 130 is typically used to physically secure the lens element to a corresponding element of the optical system (not shown). Imaging rays do not reach the mounting portion 130. The structure and shape of the mounting portion 130 are only examples to explain the technologies, and should not be taken as limiting the scope of the present disclosure. The mounting portion 130 of the lens elements discussed below may be partially or completely omitted in the following drawings.

Referring to FIG. 2 , optical axis region Z1 is defined between central point CP and first transition point TP1. Periphery region Z2 is defined between TP1 and the optical boundary OB of the surface of the lens element. Collimated ray 211 intersects the optical axis I on the image side A2 of lens element 200 after passing through optical axis region Z1, i.e., the focal point of collimated ray 211 after passing through optical axis region Z1 is on the image side A2 of the lens element 200 at point R in FIG. 2 . Accordingly, since the ray itself intersects the optical axis I on the image side A2 of the lens element 200, optical axis region Z1 is convex. On the contrary, collimated ray 212 diverges after passing through periphery region Z2. The extension line EL of collimated ray 212 after passing through periphery region Z2 intersects the optical axis I on the object side A1 of lens element 200, i.e., the focal point of collimated ray 212 after passing through periphery region Z2 is on the object side A1 at point M in FIG. 2 . Accordingly, since the extension line EL of the ray intersects the optical axis I on the object side A1 of the lens element 200, periphery region Z2 is concave. In the lens element 200 illustrated in FIG. 2 , the first transition point TP1 is the border of the optical axis region and the periphery region, i.e., TP1 is the point at which the shape changes from convex to concave.

Alternatively, there is another way for a person having ordinary skill in the art to determine whether an optical axis region is convex or concave by referring to the sign of “Radius” (the “R” value), which is the paraxial radius of shape of a lens surface in the optical axis region. The R value is commonly used in conventional optical design software such as Zemax and CodeV. The R value usually appears in the lens data sheet in the software. For an object-side surface, a positive R value defines that the optical axis region of the object-side surface is convex, and a negative R value defines that the optical axis region of the object-side surface is concave. Conversely, for an image-side surface, a positive R value defines that the optical axis region of the image-side surface is concave, and a negative R value defines that the optical axis region of the image-side surface is convex. The result found by using this method should be consistent with the method utilizing intersection of the optical axis by rays/extension lines mentioned above, which determines surface shape by referring to whether the focal point of a collimated ray being parallel to the optical axis I is on the object-side or the image-side of a lens element. As used herein, the terms “a shape of a region is convex (concave),” “a region is convex (concave),” and “a convex- (concave-) region,” can be used alternatively.

FIG. 3 , FIG. 4 and FIG. 5 illustrate examples of determining the shape of lens element regions and the boundaries of regions under various circumstances, including the optical axis region, the periphery region, and intermediate regions as set forth in the present specification.

FIG. 3 is a radial cross-sectional view of a lens element 300. As illustrated in FIG. 3 , only one transition point TP1 appears within the optical boundary OB of the image-side surface 320 of the lens element 300. Optical axis region Z1 and periphery region Z2 of the image-side surface 320 of lens element 300 are illustrated. The R value of the image-side surface 320 is positive (i.e., R>0). Accordingly, the optical axis region Z1 is concave.

In general, the shape of each region demarcated by the transition point will have an opposite shape to the shape of the adjacent region(s). Accordingly, the transition point will define a transition in shape, changing from concave to convex at the transition point or changing from convex to concave. In FIG. 3 , since the shape of the optical axis region Z1 is concave, the shape of the periphery region Z2 will be convex as the shape changes at the transition point TP1.

FIG. 4 is a radial cross-sectional view of a lens element 400. Referring to FIG. 4 , a first transition point TP1 and a second transition point TP2 are present on the object-side surface 410 of lens element 400. The optical axis region Z1 of the object-side surface 410 is defined between the optical axis I and the first transition point TP1. The R value of the object-side surface 410 is positive (i.e., R>0). Accordingly, the optical axis region Z1 is convex.

The periphery region Z2 of the object-side surface 410, which is also convex, is defined between the second transition point TP2 and the optical boundary OB of the object-side surface 410 of the lens element 400. Further, intermediate region Z3 of the object-side surface 410, which is concave, is defined between the first transition point TP1 and the second transition point TP2. Referring once again to FIG. 4 , the object-side surface 410 includes an optical axis region Z1 located between the optical axis I and the first transition point TP1, an intermediate region Z3 located between the first transition point TP1 and the second transition point TP2, and a periphery region Z2 located between the second transition point TP2 and the optical boundary OB of the object-side surface 410. Since the shape of the optical axis region Z1 is designed to be convex, the shape of the intermediate region Z3 is concave as the shape of the intermediate region Z3 changes at the first transition point TP1, and the shape of the periphery region Z2 is convex as the shape of the periphery region Z2 changes at the second transition point TP2.

FIG. 5 is a radial cross-sectional view of a lens element 500. Lens element 500 has no transition point on the object-side surface 510 of the lens element 500. For a surface of a lens element with no transition point, for example, the object-side surface 510 the lens element 500, the optical axis region Z1 is defined as the region between 0-50% of the distance between the optical axis I and the optical boundary OB of the surface of the lens element and the periphery region is defined as the region between 50%-100% of the distance between the optical axis I and the optical boundary OB of the surface of the lens element. Referring to lens element 500 illustrated in FIG. 5 , the optical axis region Z1 of the object-side surface 510 is defined between the optical axis I and 50% of the distance between the optical axis I and the optical boundary OB. The R value of the object-side surface 510 is positive (i.e., R>0). Accordingly, the optical axis region Z1 is convex. For the object-side surface 510 of the lens element 500, because there is no transition point, the periphery region Z2 of the object-side surface 510 is also convex. It should be noted that lens element 500 may have a mounting portion (not shown) extending radially outward from the periphery region Z2.

In the present disclosure, examples of an optical imaging lens are provided. Example embodiments of an optical imaging lens may comprise a first lens element, a second lens element, a third lens element, a fourth lens element, a fifth lens element, a sixth lens element, a seventh lens element and an eighth lens element. Each of the lens elements may comprise an object-side surface facing toward an object side allowing imaging rays to pass through and an image-side surface facing toward an image side allowing the imaging rays to pass through. These lens elements may be arranged sequentially from the object side to the image side along an optical axis, and example embodiments of lens elements included by the optical imaging lens may be only the eight lens elements described above. Through controlling shape of the surfaces and range of the parameters, the optical imaging lens in example embodiments may enlarge aperture stop and image height and increase resolution.

In some embodiments, the lens elements are designed with convex/concave surface shape and refracting power of lens elements in light of the optical characteristics and system length.

For example, when an optical imaging lens according to an embodiment of the invention presents negative refracting power of the fourth lens element, a concave optical axis region of the object-side surface of the fifth lens element, negative refracting power of the sixth lens element, a concave optical axis region of the image-side surface of the eighth lens element along with one of the groups: (1) a convex periphery region of the image-side surface of the sixth lens element and satisfying V1+V2+V3≤115.000, preferably 87.000 c V1+V2+V3≤115.000; (2) negative refracting power of the second lens element and satisfying V1+V3≤100.000, preferably 68.000≤V1+V3≤100.000; (3) negative refracting power of the second lens element, positive refracting power of the seventh lens element and satisfying V3+V7≤100.000, preferably 68.000≤V3+V7≤100.000, it may be beneficial to increase resolution and enlarge aperture stop and image height. When an optical imaging lens according to an embodiment of the invention presents a concave periphery region of the image-side surface of the first lens element, negative refracting power of the second lens element, a concave periphery region of the image-side surface of the third lens element, negative refracting power of the fourth lens element, a concave optical axis region of the object-side surface of the fifth lens element, a convex optical axis region of the image-side surface of the seventh lens element and satisfying V2+V3+V4+V5+V6≤175.000, preferably 125.000≤V2+V3+V4+V5+V6≤175.000, it may be beneficial to increase resolution and enlarge aperture stop and image height at the same time. When an optical imaging lens according to an embodiment of the invention presents a concave periphery region of the image-side surface of the first lens element, a concave periphery region of the image-side surface of the third lens element, negative refracting power of the fourth lens element, a concave optical axis region of the object-side surface of the fifth lens element, a convex optical axis region of the image-side surface of the seventh lens element and satisfying V1+V2+V3+V4+V5+V6≤220.000, preferably 144.000≤V1+V2+V3+V4+V5+V6≤220.000, it may be beneficial to increase resolution and enlarge aperture stop and image height at the same time. When an optical imaging lens according to an embodiment of the invention presents a concave periphery region of the image-side surface of the first lens element, negative refracting power of the second lens element, a concave periphery region of the image-side surface of the third lens element, negative refracting power of the fourth lens element, a concave optical axis region of the object-side surface of the fifth lens element, a convex optical axis region of the image-side surface of the seventh lens element, a concave periphery region of the object-side surface of the eighth lens element and satisfying V1+V2+V3+V4+V5+V6+V7+V8≤350.000, preferably 224.000 V1+V2+V3+V4+V5+V6+V7+V8≤350.000, it may be beneficial to increase resolution and enlarge aperture stop and image height at the same time. When an optical imaging lens according to an embodiment of the invention presents a concave optical axis region of the image-side surface of the first lens element, a convex periphery region of the image-side surface of the fourth lens element, positive refracting power of the fifth lens element, a concave optical axis region of the object-side surface of the fifth lens element, a convex optical axis region of the image-side surface of the seventh lens element and satisfying V3+V4+V5+V6+V7+V8≤235.000, preferably 144.000≤V3+V4+V5+V6+V7+V8≤235.000, as well as either a concave periphery region of the image-side surface of the third lens element or negative refracting power of the sixth lens element, it may be beneficial to increase resolution and enlarge aperture stop and image height at the same time. When an optical imaging lens according to an embodiment of the invention presents a concave periphery region of the image-side surface of the first lens element, negative refracting power of the second lens element, a concave periphery region of the image-side surface of the third lens element, negative refracting power of the fourth lens element, a concave optical axis region of the object-side surface of the fifth lens element, negative refracting power of the sixth lens element, a concave optical axis region of the image-side surface of the eighth lens element and satisfying V3+V5≤100.000, preferably 68.000≤V3+V5≤100.000, it may be beneficial to increase resolution and enlarge aperture stop and image height at the same time. When an optical imaging lens according to an embodiment of the invention presents negative refracting power of the second lens element, a concave optical axis region of the object-side surface of the fifth lens element, negative refracting power of the sixth lens element, a convex optical axis region of the image-side surface of the seventh lens element, a concave periphery region of the object-side surface of the eighth lens element, a concave optical axis region of the image-side surface of the eighth lens element and satisfying V3+V8≤95.000, preferably 68.000≤V3+V8≤95.000, as well as a convex periphery region of the object-side surface of the third lens element, a concave periphery region of the image-side surface of the third lens element, negative refracting power of the fourth lens element or a convex optical axis region of the object-side surface of the sixth lens element, it may be beneficial to increase resolution and enlarge aperture stop and image height at the same time.

When the optical imaging lens further satisfies at least one of the inequalities listed below, the effective focal length and each parameter may be sustained proper values to avoid any excessive value which may be unfavorable to adjust aberration of the whole system and any insufficient value which may increase the production or assembly difficulty: 3.300≤(EFL/Fno+ImgH)/D11t51, and preferably, 3.300≤(EFL/Fno+ImgH)/D11t51≤4.300; 8.750≤(EFL/Fno+ImgH)/BFL, and preferably, 8.750≤(EFL/Fno+ImgH)/BFL≤15.000.

When the optical imaging lens further satisfies at least one of the inequalities listed below, the thickness of each lens element and air gap between lens elements may be sustained proper values to avoid any excessive value which may be unfavorable to shorten system length and any insufficient value which may increase the production or assembly difficulty: D11t51/(T5+G56)≤3.600, and preferably, 1.000≤D11t51/(T5+G56)≤3.600; D12t51/(T6+G56)≤1.800, and preferably, 0.800≤D12t51/(T6+G56)≤1.800; D12t51/T8≤3.600, and preferably, 1.400≤D12t51/T8≤3.600; AAG/(T8+G78)≤2.000, and preferably, 1.100≤AAG/(T8+G78)≤2.000; (T6+G67+T7)/T1≤1.800, and preferably, 1.000≤(T6+G67+T7)/T1≤1.800; ALT/AAG≤2.200, and preferably, 1.100≤ALT/AAG≤2.200; (T2+G34+T6+G67+T7)/(T5+G56)≤2.600, and preferably, 1.000≤ (T2+G34+T6+G67+T7)/(T5+G56)≤2.600; (T2+G12+T6+G67+T7)/(T4+T5)≤2.000, and preferably, 0.800≤(T2+G12+T6+G67+T7)/(T4+T5)≤2.000; (T1+T3+T6+T7)/(G12+G78)≤9.000, and preferably, 1.100≤(T1+T3+T6+T7)/(G12+G78)≤9.000; (T3+T4+T6+T7)/(G45+G56)≤4.400, and preferably, 1.400≤(T3+T4+T6+T7)/(G45+G56)≤4.400; (G23+T3+G34+T7)/G78≤8.000, and preferably, 0.700≤(G23+T3+G34+T7)/G78≤8.000; TTL/(G56+G78)≤10.000, and preferably, 3.500≤TTL/(G56+G78)≤10.000.

In light of the unpredictability in an optical system, satisfying these inequalities listed above may result in promoting the imaging quality, shortening the system length of the optical imaging lens, lowering the f-number, increasing HFOV and/or increasing the yield in the assembly process in the present disclosure.

When implementing example embodiments, more details about the convex or concave surface or refracting power could be incorporated for one specific lens element or broadly for a plurality of lens elements to improve the control for the system volume, performance, resolution, and/or promote the yield. For example, in an example embodiment, each lens element may be made from all kinds of transparent material, such as glass, plastic, resin, etc. It is noted that the details listed here could be incorporated in example embodiments if no inconsistency occurs.

Several example embodiments and associated optical data will now be provided for illustrating example embodiments of an optical imaging lens with good optical characteristics, a wide field of view and/or a low f-number. Reference is now made to FIGS. 6-9 . FIG. 6 illustrates an example cross-sectional view of an optical imaging lens 1 having eight lens elements of the optical imaging lens according to a first example embodiment. FIG. 7 shows example charts of a longitudinal spherical aberration and other kinds of optical aberrations of the optical imaging lens 1 according to an example embodiment. FIG. 8 illustrates an example table of optical data of each lens element of the optical imaging lens 1 according to an example embodiment. FIG. 9 depicts an example table of aspherical data of the optical imaging lens 1 according to an example embodiment.

As shown in FIG. 6 , the optical imaging lens 1 of the present embodiment may comprise, in the order from an object side A1 to an image side A2 along an optical axis, an aperture stop STO, a first lens element L1, a second lens element L2, a third lens element L3, a fourth lens element L4, a fifth lens element L5, a sixth lens element L6, a seventh lens element L7 and an eighth lens element L8. A filtering unit TF and an image plane IMA of an image sensor may be positioned at the image side A2 of the optical lens 1. Each of the first, second, third, fourth, fifth, sixth, seventh and eighth lens element L1, L2, L3, L4, L5, L6, L7, L8 and the filtering unit TF may comprise an object-side surface L1A1/L2A1/L3A1/L4A1/L5A1/L6A1/L7A1/L8A1/TFA1 facing toward the object side A1 and an image-side surface L1A2/L2A2/L3A2/L4A2/L5A2/L6A2/L7A2/L8A2/TFA2 facing toward the image side A2. The filtering unit TF, positioned between the eighth lens element L8 and the image plane IMA, may selectively absorb light with specific wavelength(s) from the light passing through optical imaging lens 1. The example embodiment of the filtering unit TF which may selectively absorb light with specific wavelength(s) from the light passing through optical imaging lens 1 may be an IR cut filter (infrared cut filter). Then, IR light may be absorbed, and this may prohibit the IR light, which might not be seen by human eyes, from producing an image on the image plane IMA.

Example embodiments of each lens element of the optical imaging lens 1, which may be constructed by glass, plastic, resin material or other transparent material and is constructed by plastic material here for example, will now be described with reference to the drawings.

An example embodiment of the first lens element L1 may have positive refracting power. On the object-side surface L1A1, an optical axis region L1A1C may be convex and a periphery region L1A1P may be convex. On the image-side surface L1A2, an optical axis region L1A2C may be concave and a periphery region L1A2P may be concave.

An example embodiment of the second lens element L2 may have negative refracting power. On the object-side surface L2A1, an optical axis region L2A1C may be convex and a periphery region L2A1P may be convex. On the image-side surface L2A2, an optical axis region L2A2C may be concave and a periphery region L2A2P may be concave.

An example embodiment of the third lens element L3 may have positive refracting power. On the object-side surface L3A1, an optical axis region L3A1C may be convex and a periphery region L3A1P may be convex. On the image-side surface L3A2, an optical axis region L3A2C may be concave and a periphery region L3A2P may be concave.

An example embodiment of the fourth lens element L4 may have negative refracting power. On the object-side surface L4A1, an optical axis region L4A1C may be convex and a periphery region L4A1P may be concave. On the image-side surface L4A2, an optical axis region L4A2C may be concave and a periphery region L4A2P may be convex.

An example embodiment of the fifth lens element L5 may have positive refracting power. On the object-side surface L5A1, an optical axis region L5A1C may be concave and a periphery region L5A1P may be concave. On the image-side surface L5A2, an optical axis region L5A2C may be convex and a periphery region L5A2P may be convex.

An example embodiment of the sixth lens element L6 may have negative refracting power. On the object-side surface L6A1, an optical axis region L6A1C may be convex and a periphery region L6A1P may be concave. On the image-side surface L6A2, an optical axis region L6A2C may be concave and a periphery region L6A2P may be convex.

An example embodiment of the seventh lens element L7 may have positive refracting power. On the object-side surface L7A1, an optical axis region L7A1C may be convex and a periphery region L7A1P may be concave. On the image-side surface L7A2, an optical axis region L7A2C may be convex and a periphery region L7A2P may be convex.

An example embodiment of the eighth lens element L8 may have negative refracting power. On the object-side surface L8A1, an optical axis region L8A1C may be concave and a periphery region L8A1P may be concave. On the image-side surface L8A2, an optical axis region L8A2C may be concave and a periphery region L8A2P may be convex.

In example embodiments, air gaps may exist between each pair of adjacent lens elements, as well as between the eighth lens element L8 and the filtering unit TF, and the filtering unit TF and the image plane IMA of the image sensor. Please note, in other embodiments, any of the aforementioned air gaps may or may not exist. For example, profiles of opposite surfaces of a pair of adjacent lens elements may align with and/or attach to each other, and in such situations, the air gap might not exist.

FIG. 8 depicts the optical characteristics of each lens elements in the optical imaging lens 1 of the present embodiment. Please also refer to FIG. 38 for the values of V1+V2+V3, V1+V3, V3+V7, V3+V4+V5+V6+V7+V8, (EFL/Fno+ImgH)/D11t51, D11t51/(T5+G56), D12t51/(T6+G56), D12t51/T8, AAG/(T8+G78), V3+V8, (EFL/Fno+ImgH)/BFL, (T6+G67+T7)/T1, ALT/AAG, (T2+G34+T6+G67+T7)/(T5+G56), (T2+G12+T6+G67+T7)/(T4+T5), V3+V5, (T1+T3+T6+T7)/(G12+G78), (T3+T4+T6+T7)/(G45+G56), (G23+T3+G34+T7)/G78 and TTL/(G56+G78) corresponding to the present embodiment.

The totaled 16 aspherical surfaces, including the object-side surface L1A1 and the image-side surface L1A2 of the first lens element L1, the object-side surface L2A1 and the image-side surface L2A2 of the second lens element L2, the object-side surface L3A1 and the image-side surface L3A2 of the third lens element L3, the object-side surface L4A1 and the image-side surface L4A2 of the fourth lens element L4, the object-side surface L5A1 and the image-side surface L5A2 of the fifth lens element L5, the object-side surface L6A1 and the image-side surface L6A2 of the sixth lens element L6, the object-side surface L7A1 and the image-side surface L7A2 of the seventh lens element L7 and the object-side surface L8A1 and the image-side surface L8A2 of the eighth lens element L8 may all be defined by the following aspherical formula:

${Z(Y)} = {{\frac{Y^{2}}{R}/\left( {1 + \sqrt{1 - {\left( {1 + K} \right)\frac{Y^{2}}{R^{2}}}}} \right)} + {\sum\limits_{i = 1}^{n}{a_{i} \times Y^{i}}}}$ wherein, Y represents the perpendicular distance between the point of the aspherical surface and the optical axis; Z represents the depth of the aspherical surface (the perpendicular distance between the point of the aspherical surface at a distance Y from the optical axis and the tangent plane of the vertex on the optical axis of the aspherical surface); R represents the radius of curvature of the surface of the lens element; K represents a conic constant; a, represents an aspherical coefficient of i^(th) level. The values of each aspherical parameter are shown in FIG. 9 .

Referring to FIG. 7(a), a longitudinal spherical aberration of the optical imaging lens in the present embodiment is shown in coordinates in which the horizontal axis represents longitudinal spherical aberration and the vertical axis represents field of view, and FIG. 7(b), field curvature of the optical imaging lens in the present embodiment in the sagittal direction is shown, and FIG. 7(c), field curvature in the tangential direction of the optical imaging lens in the present embodiment is shown in coordinates in which the horizontal axis represents field curvature and the vertical axis represents image height, and FIG. 7(d), distortion aberration of the optical imaging lens in the present embodiment is shown in coordinates in which the horizontal axis represents percentage and the vertical axis represents image height. The curves of different wavelengths (470 nm, 555 nm, 650 nm) may be close to each other. This represents that off-axis light with respect to these wavelengths may be focused around an image point. From the vertical deviation of each curve shown therein, the offset of the off-axis light relative to the image point may be within −0.018˜0.018 mm. Therefore, the present embodiment may improve the longitudinal spherical aberration with respect to different wavelengths. For field curvature in the sagittal direction, the focus variation with respect to the three wavelengths in the whole field may fall within −18˜−20 μm, for field curvature in the tangential direction, the focus variation with respect to the three wavelengths in the whole field may fall within −18˜20 μm, and the variation of the distortion aberration may be within 0˜16%.

According to the values of the aberrations, it is shown that the optical imaging lens 1 of the present embodiment, with Fno as small as 1.700 and the image height as great as 6.150 mm, may be capable of providing good imaging quality.

Reference is now made to FIGS. 10-13 . FIG. 10 illustrates an example cross-sectional view of an optical imaging lens 2 having eight lens elements of the optical imaging lens according to a second example embodiment. FIG. 11 shows example charts of a longitudinal spherical aberration and other kinds of optical aberrations of the optical imaging lens 2 according to the second example embodiment. FIG. 12 shows an example table of optical data of each lens element of the optical imaging lens 2 according to the second example embodiment. FIG. 13 shows an example table of aspherical data of the optical imaging lens 2 according to the second example embodiment.

As shown in FIG. 10 , the optical imaging lens 2 of the present embodiment, in an order from an object side A1 to an image side A2 along an optical axis, may comprise an aperture stop STO, a first lens element L1, a second lens element L2, a third lens element L3, a fourth lens element L4, a fifth lens element L5, a sixth lens element L6, a seventh lens element L7 and an eighth lens element L8. The differences between the second embodiment and the first embodiment may include the radius of curvature, thickness of each lens element, the value of each air gap, aspherical data and related optical parameters, such as back focal length; but the configuration of the concave/convex shape of surfaces, comprising the object-side surfaces L1A1, L2A1, L3A1, L4A1, L5A1, L6A1, L7A1 and L8A1 facing to the object side A1 and the image-side surfaces L1A2, L2A2, L3A2, L4A2, L5A2, L6A2, L7A2 and L8A2 facing to the image side A2, and positive or negative configuration of the refracting power of each lens element may be similar to those in the first embodiment. Please refer to FIG. 12 for the optical characteristics of each lens elements in the optical imaging lens 2 of the present embodiment, and please refer to FIG. 38 for the values of V1+V2+V3, V1+V3, V3+V7, V3+V4+V5+V6+V7+V8, (EFL/Fno+ImgH)/D11t51, D11t51/(T5+G56), D12t51/(T6+G56), D12t51/T8, AAG/(T8+G78), V3+V8, (EFL/Fno+ImgH)/BFL, (T6+G67+T7)/T1, ALT/AAG, (T2+G34+T6+G67+T7)/(T5+G56), (T2+G12+T6+G67+T7)/(T4+T5), V3+V5, (T1+T3+T6+T7)/(G12+G78), (T3+T4+T6+T7)/(G45+G56), (G23+T3+G34+T7)/G78 and TTL/(G56+G78) of the present embodiment.

As the longitudinal spherical aberration shown in FIG. 11(a), the offset of the off-axis light relative to the image point may be within −0.006˜0.014 mm. As the field curvature in the sagittal direction shown in FIG. 11(b), the focus variation with regard to the three wavelengths in the whole field may fall within −0.015˜0.03 mm. As the field curvature in the tangential direction shown in FIG. 11(c), the focus variation with regard to the three wavelengths in the whole field may fall within −0.01˜0.04 mm. As shown in FIG. 11(d), the variation of the distortion aberration may be within 0˜14%. Compared with the first embodiment, the longitudinal spherical aberration and the distortion aberration of the present embodiment are smaller.

According to the values of the aberrations, it is shown that the optical imaging lens 2 of the present embodiment, with Fno as small as 1.700 and the image height as great as 6.150 mm, may be capable of providing good imaging quality.

Reference is now made to FIGS. 14-17 . FIG. 14 illustrates an example cross-sectional view of an optical imaging lens 3 having eight lens elements of the optical imaging lens according to a third example embodiment. FIG. 15 shows example charts of a longitudinal spherical aberration and other kinds of optical aberrations of the optical imaging lens 3 according to the third example embodiment. FIG. 16 shows an example table of optical data of each lens element of the optical imaging lens 3 according to the third example embodiment. FIG. 17 shows an example table of aspherical data of the optical imaging lens 3 according to the third example embodiment.

As shown in FIG. 14 , the optical imaging lens 3 of the present embodiment, in an order from an object side A1 to an image side A2 along an optical axis, may comprise an aperture stop STO, a first lens element L1, a second lens element L2, a third lens element L3, a fourth lens element L4, a fifth lens element L5, a sixth lens element L6, a seventh lens element L7 and an eighth lens element L8.

The differences between the third embodiment and the first embodiment may include the radius of curvature and thickness of each lens element, the value of each air gap, aspherical data and related optical parameters, such as back focal length; but the configuration of the concave/convex shape of surfaces, comprising the object-side surfaces L1A1, L2A1, L3A1, L4A1, L5A1, L6A1, L7A1 and L8A1 facing to the object side A1 and the image-side surfaces L1A2, L2A2, L3A2, L4A2, L5A2, L6A2, L7A2 and L8A2 facing to the image side A2, and positive or negative configuration of the refracting power of each lens element may be similar to those in the first embodiment. Please refer to FIG. 16 for the optical characteristics of each lens elements in the optical imaging lens 3 of the present embodiment, and please refer to FIG. 38 for the values of V1+V2+V3, V1+V3, V3+V7, V3+V4+V5+V6+V7+V8, (EFL/Fno+ImgH)/D11t51, D11t51/(T5+G56), D12t51/(T6+G56), D12t51/T8, AAG/(T8+G78), V3+V8, (EFL/Fno+ImgH)/BFL, (T6+G67+T7)/T1, ALT/AAG, (T2+G34+T6+G67+T7)/(T5+G56), (T2+G12+T6+G67+T7)/(T4+T5), V3+V5, (T1+T3+T6+T7)/(G12+G78), (T3+T4+T6+T7)/(G45+G56), (G23+T3+G34+T7)/G78 and TTL/(G56+G78) of the present embodiment.

As the longitudinal spherical aberration shown in FIG. 15(a), the offset of the off-axis light relative to the image point may be within −0.008˜0.014 mm. As the field curvature in the sagittal direction shown in FIG. 15(b), the focus variation with regard to the three wavelengths in the whole field may fall within −0.015˜0.02 mm. As the field curvature in the tangential direction shown in FIG. 15(c), the focus variation with regard to the three wavelengths in the whole field may fall within −0.01˜0.03 mm. As shown in FIG. 15(d), the variation of the distortion aberration may be within 0˜12%. Compared with the first embodiment, the longitudinal spherical aberration, the field curvature in the sagittal direction and the distortion aberration may be smaller in the present embodiment.

According to the values of the aberrations, it is shown that the optical imaging lens 3 of the present embodiment, with Fno as small as 1.700 and the image height as great as 6.150 mm, may be capable of providing good imaging quality.

Reference is now made to FIGS. 18-21 . FIG. 18 illustrates an example cross-sectional view of an optical imaging lens 4 having eight lens elements of the optical imaging lens according to a fourth example embodiment. FIG. 19 shows example charts of a longitudinal spherical aberration and other kinds of optical aberrations of the optical imaging lens 4 according to the fourth embodiment. FIG. 20 shows an example table of optical data of each lens element of the optical imaging lens 4 according to the fourth example embodiment. FIG. 21 shows an example table of aspherical data of the optical imaging lens 4 according to the fourth example embodiment.

As shown in FIG. 18 , the optical imaging lens 4 of the present embodiment, in an order from an object side A1 to an image side A2 along an optical axis, may comprise an aperture stop STO, a first lens element L1, a second lens element L2, a third lens element L3, a fourth lens element L4, a fifth lens element L5, a sixth lens element L6, a seventh lens element L7 and an eighth lens element L8.

The differences between the fourth embodiment and the first embodiment may include the radius of curvature and thickness of each lens element, the value of each air gap, aspherical data and related optical parameters, such as back focal length; but the configuration of the concave/convex shape of surfaces, comprising the object-side surfaces L1A1, L2A1, L3A1, L4A1, L5A1, L6A1, L7A1 and L8A1 facing to the object side A1 and the image-side surfaces L1A2, L2A2, L3A2, L4A2, L5A2, L6A2, L7A2 and L8A2 facing to the image side A2, and positive or negative configuration of the refracting power of each lens element may be similar to those in the first embodiment. Please refer to FIG. 20 for the optical characteristics of each lens elements in the optical imaging lens 4 of the present embodiment, please refer to FIGURE for the values of V1+V2+V3, V1+V3, V3+V7, V3+V4+V5+V6+V7+V8, (EFL/Fno+ImgH)/D11t51, D11t51/(T5+G56), D12t51/(T6+G56), D12t51/T8, AAG/(T8+G78), V3+V8, (EFL/Fno+ImgH)/BFL, (T6+G67+T7)/T1, ALT/AAG, (T2+G34+T6+G67+T7)/(T5+G56), (T2+G12+T6+G67+T7)/(T4+T5), V3+V5, (T1+T3+T6+T7)/(G12+G78), (T3+T4+T6+T7)/(G45+G56), (G23+T3+G34+T7)/G78 and TTL/(G56+G78) of the present embodiment.

As the longitudinal spherical aberration shown in FIG. 19(a), the offset of the off-axis light relative to the image point may be within −0.008˜0.016 mm. As the field curvature in the sagittal direction shown in FIG. 19(b), the focus variation with regard to the three wavelengths in the whole field may fall within −0.015˜0.025 mm. As the field curvature in the tangential direction shown in FIG. 19(c), the focus variation with regard to the three wavelengths in the whole field may fall within −0.01˜0.025 mm. As shown in FIG. 19(d), the variation of the distortion aberration may be within 0˜8%. Compared with the first embodiment, the longitudinal spherical aberration, the field curvature in the tangential direction and the distortion aberration may be smaller in the present embodiment.

According to the values of the aberrations, it is shown that the optical imaging lens 4 of the present embodiment, with Fno as small as 1.700 and the image height as great as 6.150 mm, may be capable of providing good imaging quality.

Reference is now made to FIGS. 22-25 . FIG. 22 illustrates an example cross-sectional view of an optical imaging lens 5 having eight lens elements of the optical imaging lens according to a fifth example embodiment. FIG. 23 shows example charts of a longitudinal spherical aberration and other kinds of optical aberrations of the optical imaging lens 5 according to the fifth embodiment. FIG. 24 shows an example table of optical data of each lens element of the optical imaging lens 5 according to the fifth example embodiment. FIG. 25 shows an example table of aspherical data of the optical imaging lens 5 according to the fifth example embodiment.

As shown in FIG. 22 , the optical imaging lens 5 of the present embodiment, in an order from an object side A1 to an image side A2 along an optical axis, may comprise an aperture stop STO, a first lens element L1, a second lens element L2, a third lens element L3, a fourth lens element L4, a fifth lens element L5, a sixth lens element L6, a seventh lens element L7 and an eighth lens element L8.

The differences between the fifth embodiment and the first embodiment may include the radius of curvature and thickness of each lens element, the value of each air gap, aspherical data, related optical parameters, such as back focal length, and the negative refracting power of the third lens element L3; but the configuration of the concave/convex shape of surfaces, comprising the object-side surfaces L1A1, L2A1, L3A1, L4A1, L5A1, L6A1, L7A1 and L8A1 facing to the object side A1 and the image-side surfaces L1A2, L2A2, L3A2, L4A2, L5A2, L6A2, L7A2 and L8A2 facing to the image side A2, and positive or negative configuration of the refracting power of each lens element other than the third lens element L3 may be similar to those in the first embodiment. Please refer to FIG. 24 for the optical characteristics of each lens elements in the optical imaging lens 5 of the present embodiment, please refer to FIG. 38 for the values of V1+V2+V3, V1+V3, V3+V7, V3+V4+V5+V6+V7+V8, (EFL/Fno+ImgH)/D11t51, D11 t51/(T5+G56), D12t51/(T6+G56), D12t51/T8, AAG/(T8+G78), V3+V8, (EFL/Fno+ImgH)/BFL, (T6+G67+T7)/T1, ALT/AAG, (T2+G34+T6+G67+T7)/(T5+G56), (T2+G12+T6+G67+T7)/(T4+T5), V3+V5, (T1+T3+T6+T7)/(G12+G78), (T3+T4+T6+T7)/(G45+G56), (G23+T3+G34+T7)/G78 and TTL/(G56+G78) of the present embodiment.

As the longitudinal spherical aberration shown in FIG. 23(a), the offset of the off-axis light relative to the image point may be within −0.08˜0.012 mm. As the field curvature in the sagittal direction shown in FIG. 23(b), the focus variation with regard to the three wavelengths in the whole field may fall within −0.01˜0.025 mm. As the field curvature in the tangential direction shown in FIG. 23(c), the focus variation with regard to the three wavelengths in the whole field may fall within −0.01˜0.03 mm. As shown in FIG. 23(d), the variation of the distortion aberration may be within 0˜9%. Compared with the first embodiment, the longitudinal spherical aberration, the field curvature in the both sagittal and tangential directions and the distortion aberration may be smaller in the present embodiment.

According to the values of the aberrations, it is shown that the optical imaging lens 5 of the present embodiment, with Fno as small as 1.700 and the image height as great as 6.150 mm, may be capable of providing good imaging quality.

Reference is now made to FIGS. 26-29 . FIG. 26 illustrates an example cross-sectional view of an optical imaging lens 6 having eight lens elements of the optical imaging lens according to a sixth example embodiment. FIG. 27 shows example charts of a longitudinal spherical aberration and other kinds of optical aberrations of the optical imaging lens 6 according to the sixth embodiment. FIG. 28 shows an example table of optical data of each lens element of the optical imaging lens 6 according to the sixth example embodiment. FIG. 29 shows an example table of aspherical data of the optical imaging lens 6 according to the sixth example embodiment.

As shown in FIG. 26 , the optical imaging lens 6 of the present embodiment, in an order from an object side A1 to an image side A2 along an optical axis, may comprise an aperture stop STO, a first lens element L1, a second lens element L2, a third lens element L3, a fourth lens element L4, a fifth lens element L5, a sixth lens element L6, a seventh lens element L7 and an eighth lens element L8.

The differences between the sixth embodiment and the first embodiment may include the radius of curvature and thickness of each lens element, the value of each air gap, aspherical data and related optical parameters, such as back focal length; but the configuration of the concave/convex shape of surfaces, comprising the object-side surfaces L1A1, L2A1, L3A1, L4A1, L5A1, L6A1, L7A1 and L8A1 facing to the object side A1 and the image-side surfaces L1A2, L2A2, L3A2, L4A2, L5A2, L6A2, L7A2 and L8A2 facing to the image side A2, and positive or negative configuration of the refracting power of each lens element except the third lens element L3 may be similar to those in the first embodiment. Please refer to FIG. 28 for the optical characteristics of each lens elements in the optical imaging lens 6 of the present embodiment, please refer to FIG. 38 for the values of V1+V2+V3, V1+V3, V3+V7, V3+V4+V5+V6+V7+V8, (EFL/Fno+ImgH)/D11t51, D11t51/(T5+G56), D12t51/(T6+G56), D12t51/T8, AAG/(T8+G78), V3+V8, (EFL/Fno+ImgH)/BFL, (T6+G67+T7)/T1, ALT/AAG, (T2+G34+T6+G67+T7)/(T5+G56), (T2+G12+T6+G67+T7)/(T4+T5), V3+V5, (T1+T3+T6+T7)/(G12+G78), (T3+T4+T6+T7)/(G45+G56), (G23+T3+G34+T7)/G78 and TTL/(G56+G78) of the present embodiment.

As the longitudinal spherical aberration shown in FIG. 27(a), the offset of the off-axis light relative to the image point may be within −0.018˜0.012 mm. As the field curvature in the sagittal direction shown in FIG. 27(b), the focus variation with regard to the three wavelengths in the whole field may fall within −0.02˜0.03 mm. As the field curvature in the tangential direction shown in FIG. 27(c), the focus variation with regard to the three wavelengths in the whole field may fall within −0.02˜0.06 mm. As shown in FIG. 27(d), the variation of the distortion aberration may be within −2˜3.5%. Compared with the first embodiment, the longitudinal spherical aberration and the distortion aberration may be smaller in the present embodiment.

According to the values of the aberrations, it is shown that the optical imaging lens 6 of the present embodiment, with Fno as small as 1.700 and the image height as great as 5.350 mm, may be capable of providing good imaging quality.

Reference is now made to FIGS. 30-33 . FIG. 30 illustrates an example cross-sectional view of an optical imaging lens 7 having eight lens elements of the optical imaging lens according to a seventh example embodiment. FIG. 31 shows example charts of a longitudinal spherical aberration and other kinds of optical aberrations of the optical imaging lens 7 according to the seventh embodiment. FIG. 32 shows an example table of optical data of each lens element of the optical imaging lens 7 according to the seventh example embodiment. FIG. 33 shows an example table of aspherical data of the optical imaging lens 7 according to the seventh example embodiment.

As shown in FIG. 30 , the optical imaging lens 7 of the present embodiment, in an order from an object side A1 to an image side A2 along an optical axis, may comprise an aperture stop STO, a first lens element L1, a second lens element L2, a third lens element L3, a fourth lens element L4, a fifth lens element L5, a sixth lens element L6, a seventh lens element L7 and an eighth lens element L8.

The differences between the seventh embodiment and the first embodiment may include the radius of curvature and thickness of each lens element, the value of each air gap, aspherical data, related optical parameters, such as back focal length, and the configuration of the concave/convex shape of the object-side surface L3A1; but the configuration of the concave/convex shape of surfaces, comprising the object-side surfaces L1A1, L2A1, L4A1, L5A1, L6A1, L7A1 and L8A1 facing to the object side A1 and the image-side surfaces L1A2, L2A2, L3A2, L4A2, L5A2, L6A2, L7A2 and L8A2 facing to the image side A2, and positive or negative configuration of the refracting power of each lens element may be similar to those in the first embodiment. Here and in the embodiments hereinafter, for clearly showing the drawings of the present embodiment, only the surface shapes which are different from that in the first embodiment may be labeled. Specifically, a periphery region L3A1P of the object-side surface L3A1 of the third lens element L3 may be concave. Please refer to FIG. 32 for the optical characteristics of each lens elements in the optical imaging lens 7 of the present embodiment, please refer to FIG. 38 for the values of V1+V2+V3, V1+V3, V3+V7, V3+V4+V5+V6+V7+V8, (EFL/Fno+ImgH)/D11t51, D11t51/(T5+G56), D12t51/(T6+G56), D12t51/T8, AAG/(T8+G78), V3+V8, (EFL/Fno+ImgH)/BFL, (T6+G67+T7)/T1, ALT/AAG, (T2+G34+T6+G67+T7)/(T5+G56), (T2+G12+T6+G67+T7)/(T4+T5), V3+V5, (T1+T3+T6+T7)/(G12+G78), (T3+T4+T6+T7)/(G45+G56), (G23+T3+G34+T7)/G78 and TTL/(G56+G78) of the present embodiment.

As the longitudinal spherical aberration shown in FIG. 31(a), the offset of the off-axis light relative to the image point may be within −0.01˜0.014 mm. As the field curvature in the sagittal direction shown in FIG. 31(b), the focus variation with regard to the three wavelengths in the whole field may fall within −0.02˜0.02 mm. As the field curvature in the tangential direction shown in FIG. 31(c), the focus variation with regard to the three wavelengths in the whole field may fall within −0.01˜0.06 mm. As shown in FIG. 31(d), the variation of the distortion aberration may be within −6˜4%. Compared with the first embodiment, the longitudinal spherical aberration and the distortion aberration may be smaller in the present embodiment.

According to the values of the aberrations, it is shown that the optical imaging lens 7 of the present embodiment, with Fno as small as 1.700 and the image height as great as 5.029 mm, may be capable of providing good imaging quality.

Reference is now made to FIGS. 34-37 . FIG. 34 illustrates an example cross-sectional view of an optical imaging lens 8 having eight lens elements of the optical imaging lens according to an eighth example embodiment. FIG. 35 shows example charts of a longitudinal spherical aberration and other kinds of optical aberrations of the optical imaging lens 8 according to the eighth embodiment. FIG. 36 shows an example table of optical data of each lens element of the optical imaging lens 8 according to the eighth example embodiment. FIG. 37 shows an example table of aspherical data of the optical imaging lens 8 according to the eighth example embodiment.

As shown in FIG. 34 , the optical imaging lens 8 of the present embodiment, in an order from an object side A1 to an image side A2 along an optical axis, may comprise an aperture stop STO, a first lens element L1, a second lens element L2, a third lens element L3, a fourth lens element L4, a fifth lens element L5, a sixth lens element L6, a seventh lens element L7 and an eighth lens element L8.

The differences between the eighth embodiment and the first embodiment may include the radius of curvature and thickness of each lens element, the value of each air gap, aspherical data, related optical parameters, such as back focal length, the configuration of the concave/convex shape of the object-side surface L8A1, and the negative refracting power of the fifth lens element L5; but the configuration of the concave/convex shape of surfaces comprising the object-side surfaces L1A1, L2A1, L3A1, L4A1, L5A1, L6A1 and L7A1 facing to the object side A1 and the image-side surfaces L1A2, L2A2, L3A2, L4A2, L5A2, L6A2, L7A2 and L8A2 facing to the image side A2, and positive or negative configuration of the refracting power of each lens element other than the fifth lens element L5 may be similar to those in the first embodiment. Specifically, a periphery region L8A1P of the object-side surface L8A1 of the eighth lens element L8 may be convex. Please refer to FIG. 36 for the optical characteristics of each lens elements in the optical imaging lens 8 of the present embodiment, and please refer to FIG. 38 for the values of V1+V2+V3, V1+V3, V3+V7, V3+V4+V5+V6+V7+V8, (EFL/Fno+ImgH)/D11t51, D11t51/(T5+G56), D12t51/(T6+G56), D12t51/T8, AAG/(T8+G78), V3+V8, (EFL/Fno+ImgH)/BFL, (T6+G67+T7)/T1, ALT/AAG, (T2+G34+T6+G67+T7)/(T5+G56), (T2+G12+T6+G67+T7)/(T4+T5), V3+V5, (T1+T3+T6+T7)/(G12+G78), (T3+T4+T6+T7)/(G45+G56), (G23+T3+G34+T7)/G78 and TTL/(G56+G78) of the present embodiment.

As the longitudinal spherical aberration shown in FIG. 35(a), the offset of the off-axis light relative to the image point may be within −0.035˜0.015 mm. As the field curvature in the sagittal direction shown in FIG. 35(b), the focus variation with regard to the three wavelengths in the whole field may fall within −0.04˜−0.03 mm. As the field curvature in the tangential direction shown in FIG. 35(c), the focus variation with regard to the three wavelengths in the whole field may fall within −0.09˜0.03 mm. As shown in FIG. 35(d), the variation of the distortion aberration may be within −6˜2%. Compared with the first embodiment, the distortion aberration is smaller in the present embodiment.

According to the values of the aberrations, it is shown that the optical imaging lens 8 of the present embodiment, with Fno as small as 1.800 and the image height as great as 5.463 mm, may be capable of providing good imaging quality.

Please refer to FIG. 38 for the values of V1+V2+V3, V1+V3, V3+V7, V3+V4+V5+V6+V7+V8, (EFL/Fno+ImgH)/D11t51, D11t51/(T5+G56), D12t51/(T6+G56), D12t51/T8, AAG/(T8+G78), V3+V8, (EFL/Fno+ImgH)/BFL, (T6+G67+T7)/T1, ALT/AAG, (T2+G34+T6+G67+T7)/(T5+G56), (T2+G12+T6+G67+T7)/(T4+T5), V3+V5, (T1+T3+T6+T7)/(G12+G78), (T3+T4+T6+T7)/(G45+G56), (G23+T3+G34+T7)/G78 and TTL/(G56+G78) of all eight embodiments, and the optical imaging lens of the present disclosure may satisfy at least one of Inequalities (1)˜(20). Further, any range of which the upper and lower limits defined by the values disclosed in all of the embodiments herein may be implemented in the present embodiments.

According to above illustration, the longitudinal spherical aberration, field curvature in both the sagittal direction and tangential direction and distortion aberration in all embodiments may meet the user requirement of a related product in the market. The off-axis light with regard to three different wavelengths (470 nm, 555 nm, 650 nm) may be focused around an image point and the offset of the off-axis light relative to the image point may be well controlled with suppression for the longitudinal spherical aberration, field curvature both in the sagittal direction and tangential direction and distortion aberration. The curves of different wavelengths may be close to each other, and this represents that the focusing for light having different wavelengths may be good to suppress chromatic dispersion. In summary, lens elements are designed and matched for achieving good imaging quality.

While various embodiments in accordance with the disclosed principles are described above, it should be understood that they are presented by way of example only, and are not limiting. Thus, the breadth and scope of example embodiment(s) should not be limited by any of the above-described embodiments, but should be defined only in accordance with the claims and their equivalents issuing from this disclosure. Furthermore, the above advantages and features are provided in described embodiments, but shall not limit the application of such issued claims to processes and structures accomplishing any or all of the above advantages. Further, all of the numerical ranges including the maximum and minimum values and the values therebetween which are obtained from the combining proportion relation of the optical parameters disclosed in each embodiment of the present disclosure are implementable.

Additionally, the section headings herein are provided for consistency with the suggestions under 37 C.F.R. 1.77 or otherwise to provide organizational cues. These headings shall not limit or characterize the invention(s) set out in any claims that may issue from this disclosure. Specifically, a description of a technology in the “Background” is not to be construed as an admission that technology is prior art to any invention(s) in this disclosure. Furthermore, any reference in this disclosure to “invention” in the singular should not be used to argue that there is only a single point of novelty in this disclosure. Multiple inventions may be set forth according to the limitations of the multiple claims issuing from this disclosure, and such claims accordingly define the invention(s), and their equivalents, that are protected thereby. In all instances, the scope of such claims shall be considered on their own merits in light of this disclosure, but should not be constrained by the headings herein. 

What is claimed is:
 1. An optical imaging lens, comprising a first lens element, a second lens element, a third lens element, a fourth lens element, a fifth lens element, a sixth lens element, a seventh lens element and an eighth lens element sequentially from an object side to an image side along an optical axis, each of the first, second, third, fourth, fifth, sixth, seventh and eighth lens element having an object-side surface facing toward the object side and allowing imaging rays to pass through and an image-side surface facing toward the image side and allowing the imaging rays to pass through, wherein: the fourth lens element has negative refracting power; an optical axis region of the object-side surface of the fifth lens element is concave; the sixth lens element has negative refracting power and a periphery region of the image-side surface of the sixth lens element is convex; and an optical axis region of the image-side surface of the eighth lens element is concave; lens elements included by the optical imaging lens are only the eight lens elements described above; and an abbe number of the first lens element is represented by V1, an abbe number of the second lens element is represented by V2, an abbe number of the third lens element is represented by V3, and the optical imaging lens satisfies the inequality: V1+V2+V3≤115.000.
 2. The optical imaging lens according to claim 1, wherein a an abbe number of the fourth lens element is represented by V4, an abbe number of the fifth lens element is represented by V5, an abbe number of the sixth lens element is represented by V6, an abbe number of the seventh lens element is represented by V7, an abbe number of the eighth lens element is represented by V8, and V3, V4, V5, V6, V7 and V8 satisfy the inequality: V3+V4+V5+V6+V7+V8≤235.000.
 3. The optical imaging lens according to claim 1, wherein an effective focal length of the optical imaging lens is represented by EFL, a f-number of the optical imaging lens is represented by Fno, an image height of the optical imaging lens is represented by ImgH, a distance from the object-side surface of the first lens element to the object-side surface of the fifth lens element along the optical axis is represented by D11t51, and EFL, Fno, ImgH and D11t51 satisfy the inequality: 3.300≤(EFL/Fno+ImgH)/D11t51.
 4. The optical imaging lens according to claim 1, wherein a distance from the object-side surface of the first lens element to the object-side surface of the fifth lens element along the optical axis is represented by D11t51, a thickness of the fifth lens element along the optical axis is represented by T5, a distance from the image-side surface of the fifth lens element to the object-side surface of the sixth lens element along the optical axis is represented by G56, and D11t51, T5 and G56 satisfy the inequality: D11t51/(T5+G56)≤3.600.
 5. The optical imaging lens according to claim 1, wherein a distance from the image-side surface of the first lens element to the object-side surface of the fifth lens element along the optical axis is represented by D12t51, a thickness of the sixth lens element along the optical axis is represented by T6, a distance from the image-side surface of the fifth lens element to the object-side surface of the sixth lens element along the optical axis is represented by G56, and D11t51, T6 and G56 satisfy the inequality: D12t51/(T6+G56)≤1.800.
 6. The optical imaging lens according to claim 1, wherein a distance from the image-side surface of the first lens element to the object-side surface of the fifth lens element along the optical axis is represented by D12t51, a thickness of the eighth lens element along the optical axis is represented by T8, and D12t51 and T8 satisfy the inequality: D12t51/T8≤3.600.
 7. The optical imaging lens according to claim 1, wherein a thickness of the eighth lens element along the optical axis is represented by T8, a sum of seven air gaps from the first lens element to the eighth lens element along the optical axis is represented by AAG, a distance from the image-side surface of the seventh lens element to the object-side surface of the eighth lens element along the optical axis is represented by G78, and AAG, T8 and G78 satisfy the inequality: AAG/(T8+G78)≤2.000.
 8. The optical imaging lens according to claim 1, wherein: the second lens element has negative refracting power; and an abbe number of the first lens element is represented by V1, an abbe number of the third lens element is represented by V3, and the optical imaging lens satisfies the inequalities: V1+V3≤100.000.
 9. The optical imaging lens according to claim 8, wherein an abbe number of the eighth lens element is represented by V8, and V3 and V8 satisfy the inequality: V3+V8≤95.000.
 10. The optical imaging lens according to claim 8, wherein an effective focal length of the optical imaging lens is represented by EFL, a f-number of the optical imaging lens is represented by Fno, an image height of the optical imaging lens is represented by ImgH, a distance from the image-side surface of the eighth lens element to an image plane along the optical axis is represented by BFL, and EFL, Fno, ImgH and BFL satisfy the inequality: 8.750≤(EFL/Fno+ImgH)/BFL.
 11. The optical imaging lens according to claim 8, wherein a thickness of the sixth lens element along the optical axis is represented by T6, a distance from the image-side surface of the sixth lens element to the object-side surface of the seventh lens element along the optical axis is represented by G67, a thickness of the seventh lens element along the optical axis is represented by T7, a thickness of the first lens element along the optical axis is represented by T1, and T6, G67, T7 and T1 satisfy the inequality: (T6+G67+T7)/T1≤1.800.
 12. The optical imaging lens according to claim 8, wherein a sum of the thicknesses of all eight lens elements along the optical axis is represented by ALT, a sum of seven air gaps from the first lens element to the eighth lens element along the optical axis is represented by AAG, and ALT and AAG satisfy the inequality: ALT/AAG≤2.200.
 13. The optical imaging lens according to claim 8, wherein a thickness of the second lens element along the optical axis is represented by T2, a distance from the image-side surface of the third lens element to the object-side surface of the fourth lens element along the optical axis is represented by G34, a thickness of the sixth lens element along the optical axis is represented by T6, a distance from the image-side surface of the sixth lens element to the object-side surface of the seventh lens element along the optical axis is represented by G67, a thickness of the seventh lens element along the optical axis is represented by T7, a thickness of the fifth lens element along the optical axis is represented by T5, a distance from the image-side surface of the fifth lens element to the object-side surface of the sixth lens element along the optical axis is represented by G56, and T2, G34, T6, G67, T7, T5 and G56 satisfy the inequality: (T2+G34+T6+G67+T7)/(T5+G56)≤2.600.
 14. The optical imaging lens according to claim 8, wherein a thickness of the second lens element along the optical axis is represented by T2, a distance from the image-side surface of the first lens element to the object-side surface of the second lens element along the optical axis is represented by G12, a thickness of the sixth lens element along the optical axis is represented by T6, a distance from the image-side surface of the sixth lens element to the object-side surface of the seventh lens element along the optical axis is represented by G67, a thickness of the seventh lens element along the optical axis is represented by T7, a thickness of the fourth lens element along the optical axis is represented by T4, a thickness of the fifth lens element along the optical axis is represented by T5, and T2, G12, T6, G67, T7, T4 and T5 satisfy the inequality: (T2+G12+T6+G67+T7)/(T4+T5)≤2.000.
 15. The optical imaging lens according to claim 1, wherein: the second lens element has negative refracting power; the seventh lens element has positive refracting power; and an abbe number of the seventh lens element is represented by V7, and the optical imaging lens satisfies the inequalities: V3+V7≤100.000.
 16. The optical imaging lens according to claim 15, wherein an abbe number of the fifth lens element is represented by V5, and V3 and V5 satisfy the inequality: V3+V5≤100.000.
 17. The optical imaging lens according to claim 15, wherein a thickness of the first lens element along the optical axis is represented by T1, a thickness of the third lens element along the optical axis is represented by T3, a thickness of the sixth lens element along the optical axis is represented by T6, a thickness of the seventh lens element along the optical axis is represented by T7, a distance from the image-side surface of the first lens element to the object-side surface of the second lens element along the optical axis is represented by G12, a distance from the image-side surface of the seventh lens element to the object-side surface of the eighth lens element along the optical axis is represented by G78, and T1, T3, T6, T7, G12 and G78 satisfy the inequality: (T1+T3+T6+T7)/(G12+G78)≤9.000.
 18. The optical imaging lens according to claim 15, wherein a thickness of the third lens element along the optical axis is represented by T3, a thickness of the fourth lens element along the optical axis is represented by T4, a thickness of the sixth lens element along the optical axis is represented by T6, a thickness of the seventh lens element along the optical axis is represented by T7, a distance from the image-side surface of the fourth lens element to the object-side surface of the fifth lens element along the optical axis is represented by G45, a distance from the image-side surface of the fifth lens element to the object-side surface of the sixth lens element along the optical axis is represented by G56, and T3, T4, T6, T7, G45 and G56 satisfy the inequality: (T3+T4+T6+T7)/(G45+G56)≤4.400.
 19. The optical imaging lens according to claim 15, wherein a distance from the image-side surface of the second lens element to the object-side surface of the third lens element along the optical axis is represented by G23, a thickness of the third lens element along the optical axis is represented by T3, a distance from the image-side surface of the third lens element to the object-side surface of the fourth lens element along the optical axis is represented by G34, a thickness of the seventh lens element along the optical axis is represented by T7, a distance from the image-side surface of the seventh lens element to the object-side surface of the eighth lens element along the optical axis is represented by G78, and G23, T3, G34, T7 and G78 satisfy the inequality: (G23+T3+G34+T7)/G78≤8.000.
 20. The optical imaging lens according to claim 15, wherein a distance from the object-side surface of the first lens element to an image plane along the optical axis is represented by TTL, a distance from the image-side surface of the fifth lens element to the object-side surface of the sixth lens element along the optical axis is represented by G56, a distance from the image-side surface of the seventh lens element to the object-side surface of the eighth lens element along the optical axis is represented by G78, and TTL, G56 and G78 satisfy the inequality: TTL/(G56+G78)≤10.000. 